On 2023-07-05 09:54, ggl329 via Cygwin wrote:
Hi Mark,
On 2023/07/05 12:06, Mark Geisert via Cygwin wrote:
My previous reply addressed the specific error reported by your testcase.
But I am unable to make progress on the root cause because I can't reproduce
your report.
Hm, it seems to be difficult to track down the root cause...
On my system I try the compilation and see:
~ clang++ sample.cc
sample.cc:1:10: fatal error: 'iostream' file not found
#include <iostream>
^~~~~~~~~~
1 error generated.
I tried with clang++ --verbose, and the log showed search paths for #include.
iostream is at /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/iostream.
Can you find it? It comes from gcc-g++.
Or the search path includes /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++?
Package clang pulls in headers and libraries from libc++-devel libclang8
libunwind-devel gcc-g++ libstdc++6 gcc-core cygwin-devel so the primary include
paths should be from:
libc++-devel /usr/include/c++/v1/ for most language and library definitions and
libraries,
libclang8 /usr/lib/clang/8.0.1/include/ for clang intrinsics and builtins,
libunwind-devel /usr/include/ for exception handling definitions and libraries,
gcc-g++ /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/{x86_64-pc-cygwin/,} and
libstdc++6 for C++ system dependent and low level definitions and libraries,
gcc-core /usr/lib/gcc/x86_64-pc-cygwin/11/include/ for system dependent and low
level intrinsics and interfaces, and
cygwin-devel /usr/include/{*/,} for system dependent and low level definitions
and libraries.
Everything clang should be prioritized over anything gcc to prevent such issues,
so cygcheck -c clang llvm libc++-devel libclang8 libunwind-devel gcc-g++
libstdc++6 gcc-core cygwin-devel to ensure eveything has been installed properly.
Unfortunately clang{,++,-cpp} -print-search-dirs does *NOT* show include paths,
but -v and -### complain about nonexistent /usr/include/c++/11 where
/usr/include/c++/v1 exists!
It appears the search list ignores the directories populated in libc++-devel:
... -resource-dir /usr/lib/clang/8.0.1
-internal-isystem /usr/x86_64-pc-cygwin/include/c++
-internal-isystem /usr/x86_64-pc-cygwin/include/c++/x86_64-pc-cygwin
-internal-isystem /usr/x86_64-pc-cygwin/include/c++/backward
-internal-isystem /usr/x86_64-pc-cygwin/include/c++/11
-internal-isystem /usr/x86_64-pc-cygwin/include/c++/11/x86_64-pc-cygwin
-internal-isystem /usr/x86_64-pc-cygwin/include/c++/11/backward
-internal-isystem /usr/include/c++/11
-internal-isystem /usr/include/c++/11/x86_64-pc-cygwin
-internal-isystem /usr/include/c++/11/backward
-internal-isystem /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++
-internal-isystem /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/x86_64-pc-cygwin
-internal-isystem /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/backward
-internal-isystem /usr/lib/clang/8.0.1/include
-internal-isystem /usr/local/include
-internal-isystem /usr/lib/clang/8.0.1/include
-internal-isystem /usr/x86_64-pc-cygwin/include
-internal-isystem /usr/include
-internal-isystem /usr/include/w32api ...
ignoring nonexistent directory "/usr/x86_64-pc-cygwin/include/c++"
ignoring nonexistent directory
"/usr/x86_64-pc-cygwin/include/c++/x86_64-pc-cygwin"
ignoring nonexistent directory "/usr/x86_64-pc-cygwin/include/c++/backward"
ignoring nonexistent directory "/usr/x86_64-pc-cygwin/include/c++/11"
ignoring nonexistent directory
"/usr/x86_64-pc-cygwin/include/c++/11/x86_64-pc-cygwin"
ignoring nonexistent directory "/usr/x86_64-pc-cygwin/include/c++/11/backward"
ignoring nonexistent directory "/usr/include/c++/11"
ignoring nonexistent directory "/usr/include/c++/11/x86_64-pc-cygwin"
ignoring nonexistent directory "/usr/include/c++/11/backward"
ignoring nonexistent directory "/usr/x86_64-pc-cygwin/include"
ignoring duplicate directory "/usr/lib/clang/8.0.1/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/lib/gcc/x86_64-pc-cygwin/11/include/c++
/usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/x86_64-pc-cygwin
/usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/backward
/usr/lib/clang/8.0.1/include
/usr/local/include
/usr/include
/usr/include/w32api
End of search list.
You may want to try to override the built in includes from -internal-isystem
with those mentioned above but not built in.
I have no idea why both compilers would include w32api headers as if they were
building Mingw cross compilers!
--
Take care. Thanks, Brian Inglis Calgary, Alberta, Canada
La perfection est atteinte Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer but when there is no more to cut
-- Antoine de Saint-Exupéry
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